Air cleaner and method of filtering

ABSTRACT

A filter element, a safety element and fluid cleaner assembly. The fluid cleaner assembly generally includes a housing having a cover and a primary fluid cleaner section. The element generally includes a z-filter media, arranged in a straight through configuration, and an axial seal gasket positioned to extend continuously around an outer perimeter of the straight through flow construction. The fluid cleaner assembly can have a precleaner positioned therein. Methods of assembly and use are provided.

CLAIMS TO PRIORITY

This application is a continuation of application Ser. No. 10/405,432,filed Apr. 2, 2003 now U.S. Pat. No. 6,966,940, Application Ser. No.10/405,432 claims priority to U.S. provisional applications Ser. No.60/370,438, filed Apr. 4, 2002, and Ser. No. 60/426,071, filed Nov. 12,2002. Each of the disclosures of application Ser. Nos. 10/405,432;60/370,438; and 60/426,071 is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to filter constructions for filteringfluids, such as liquids or gases. This particular disclosure concerns:straight through flow filter elements; safety filter elements;assemblies employing such elements; precleaners; and methods for using,and assembly of, such filter elements.

BACKGROUND

Straight through flow filter elements have been used in various systemsfor filtering fluids such as gases or liquids. Straight through flowfilter elements typically have an inlet face (or end) and an oppositelydisposed outlet face (or end). During filtering, the fluid to befiltered flows in one direction upon entering the filter element at theinlet face, and has the same general direction of flow as it exits theoutlet face. Typically, a straight through flow filter element isinstalled in a housing, for use. After a period of use, the filterelement requires servicing, either through cleaning or completereplacement of the filter element. A seal is necessary between theelement and a portion of the housing in which the element is placed inuse, to ensure proper filtering of the fluid flow through thearrangement.

Improvements in straight through flow filter elements, their assemblyand their use are desirable.

SUMMARY

According to the present disclosure a filter element is provided. Thefilter element in general has a straight through flow construction andcomprises z-filter media. The filter element includes a seal gasket.

The current disclosure also concerns air cleaner assemblies. In generalthe air cleaner assembly includes a housing comprising a cover and aprimary air cleaner section. A primary filter element is positionedwithin the housing such that an axial seal or pinch seal gasket thereonis positioned between the cover and the primary air cleaner section. Incertain preferred arrangements, the cover comprises a precleaner,preferably including a plurality of cyclonic air separators therein anda dust ejector thereon.

In certain preferred embodiments the primary air filter, within thehousing, has a race track shape.

The current disclosure also concerns safety elements.

Methods of assembly and use are also provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side perspective view of an air cleaner arrangementaccording to the present disclosure;

FIG. 2 is an exploded, perspective view of the air cleaner arrangementdepicted in FIG. 1, the precleaner, primary filter element, and safetyfilter element being viewable;

FIG. 3 is an inlet end view of the air cleaner arrangement depicted inFIG. 1;

FIG. 4 is a cross-sectional view of the air cleaner arrangement depictedin FIG. 1, the cross-section being taken along the line 4—4 of FIG. 3;

FIG. 5 is a schematic, perspective view of Z-media, a type of mediausable in the primary filter element, according to the presentdisclosure;

FIG. 6 is an inlet end view of the primary filter element viewable inFIG. 2;

FIG. 7 is a cross-sectional view of the primary filter element of FIG.6, the cross-section being taken along the line 7—7 of FIG. 6;

FIG. 8 is an enlarged fragmentary view showing an interaction between agasket member mounted on the primary filter element and structuralmembers on certain housing components;

FIG. 9 is a fragmentary, cross-sectional view of an alternate embodimentof a gasket member usable herein;

FIG. 10 is an enlarged, fragmentary view analogous to the view shown inFIG. 8, but depicting the alternate gasket arrangement shown in FIG. 9;

FIG. 11 is a perspective view of a safety filter element usable in theair cleaner arrangement depicted in FIG. 2;

FIG. 12 is a longitudinal cross-sectional view of the safety filterelement depicted in FIG. 11;

FIG. 13 is an end view of the safety filter element of FIG. 11;

FIG. 14 is a side elevational view of the safety filter element depictedin FIG. 11;

FIG. 15 is a perspective view of the primary filter element and safetyfilter element while engaged with each other;

FIG. 16 is a perspective view showing the primary filter element andsafety filter element engaged with each other, from an oppositeperspective from that of FIG. 15;

FIG. 17 depicts a side elevational view of the primary filter elementand safety filter element engaged as shown in FIGS. 15 and 16;

FIG. 18 is a top plan view of the filter elements depicted in FIG. 17;

FIG. 19 is a bottom plan view of the arrangement of FIG. 17;

FIG. 20 is a cross-sectional view of the primary filter element andsafety filter element interacting, the cross-section being taken alongthe line 20—20 of FIG. 18;

FIG. 21 is a side-elevational view of the primary filter element andsafety filter element engaging; and

FIG. 22 is a cross-sectional view of the arrangement of FIG. 21, thecross-section being taken along the line 22—22 of FIG. 21.

DETAILED DESCRIPTION

A. Overview

In general, the techniques described herein are applicable to fluidcleaners. There are generally two classes of fluid cleaners with whichthe techniques can be applied, namely liquid cleaners and gas cleaners.The embodiment depicted is specifically of an air cleaner (i.e., a typeof gas cleaner), and thus the features will be described in thiscontext. Applicability of the principles and techniques described toliquid cleaners or to cleaners of other gases, will be apparent from thegeneral descriptions.

Reference numeral 1, FIG. 1, indicates an air cleaner arrangementaccording to present disclosure. The air cleaner arrangement 1 generallycomprises: a housing 2, an outlet flow duct 3, and a dust ejector 4. Ingeneral, the air cleaner arrangement 1 also includes, within the housing2, as described below, a serviceable (primary) filter element componentand an optional, serviceable safety (or secondary) filter elementcomponent. Herein the term “primary” when used to refer to a filterelement, is meant to refer to a filter element which conducts majorityof the filtering within the assembly. In this instance by “filtering”what is meant is removal of particulate material by passage of fluidflow through media. The term “serviceable” in this context is meant torefer to a filter element that is configured to be periodically removedand replaced. (That is, the air cleaner can be serviced by removing oneelement and installing another.) Safety element or secondary elementhelps to protect downstream components of the equipment on which the aircleaner assembly 1 is installed, in case of failure of the primaryelement.

Still referring to FIG. 1, in general the air cleaner 1 depicted is apreferred two-stage air cleaner having a cover 7, in this instance aprecleaner section 8, and a primary air cleaner section 9. Theparticular housing 2 depicted is jointed between the cover 7 and theprimary air cleaner section 9, at joint or region 11. At housing joint11, the cover 7 and the primary air cleaner section 9 can be opened orseparated, for access to an internally received filter elementcomponent, for servicing. This is described in greater detail below.Herein a step of pivoting, or in some instances even removing, a housingcover 7 relative to the primary filter element containing section 9,will be referred to as obtaining service access to aninternally-received filter element component, or alternatively as“opening” the air cleaner 1, for example for servicing.

In general, air to be filtered enters air cleaner assembly 1 at end 12,by passage into individual cyclonic or centrifugal separators 13, inprecleaner 8. Separators of the type usable at reference 13 could beconventional, and a variety of types may be used, for example those inU.S. Pat. Nos. 4,242,115 and 4,746,340, both of which are incorporatedherein by reference. However, the particular precleaner 8 shown can leadto advantages. Within the separators 13, a first stage dust separationor precleaning occurs, and dust separated at this location is ejectedfrom the precleaner 8 through dust ejector 4, in particular throughejector tube 14 and ejector valve 15. Of course, the process conductedin the precleaner 8 is not “filtering” as the term was defined above,since the dust separation in the precleaner results from a centrifugalor cyclonic process, as opposed to a process of passing the fluidthrough a media. The particular precleaner 8 shown is described inSection D below.

Air that is passed out of the precleaner 8, into the primary air cleanersection 9, is then passed through an internally received primary filterelement, described in Section B below, through optional safety element(described in Section C below), and eventually into a clean air regionfor exiting through clean air outlet duct 3. From duct 3, the clean aircan be directed to whatever equipment is downstream, for example anengine air intake of an internal combustion engine.

Referring to FIGS. 1 and 2, in general cover 7 is pivotally secured onprimary air cleaner section 9 by supports 16 and over center clamps 17.Once the over center clamps 17 are released, the cover 7 can be openedrelative to the primary air cleaner section 9 of housing 2, by pivotingthe cover 7 (or precleaner 8) relative to the support 16. Alternately,the system can be configured for complete separation of the cover 7during opening.

Referring to FIG. 1, the assembly 1 can be mounted on various machineryparts by mounting pads 19, for example using bolts. In general, aircleaner 1 will be mounted with ejector tube 14 and dust ejector 15directed generally downwardly, to facilitate dust ejection.

Attention is now directed to FIG. 4, which is a cross-sectional view ofthe assembly 1 depicted from the view point of line 4—4, FIG. 3.Referring to FIG. 4, precleaner 8 is shown mounted on primary aircleaner section 9, with internally received primary filter element 22depicted and internally received safety filter element 20 depicted.

B. Usable Primary Filter Elements

The filter element 22 is configured to permit straight through flow;that is, it has a straight through flow construction. By the term“straight through flow,” in this context, it is meant that the fluidswhich flow to the filter element 22, for filtering, enter the filterelement 22 at inlet end or face 23 in a first direction and exit fromopposite outlet end or face 24 with flow in the same general direction.The term “straight through flow” as characterized above, is meant tospecifically differentiate a flow in a system such as that described inWO 89/01818 published 9 Mar. 1989, in which air enters a cylindricalpleated filter member by direction against a cylindrical surface, andthen exits the element (for example through an aperture) after making anapproximately 90° turn.

The filter element 22 includes a filter construction having an outersidewall or surface 25 and comprising filter media 26 that is configuredto filter particulates from a gas stream entering the inlet end or face23, such that the gas stream exiting the outlet end or face 24 is atleast partially clean (i.e., free of particulates). As can also be seenfrom FIG. 2, the filter element 22 also includes a gasket or seal member28 which aids in inhibiting leakage between the filter element 22 andportions of the housing 2 in which the filter element 22 is installed.The preferred gasket 28 extends completely, peripherally, around theouter sidewall 25 of the straight through flow construction or element22.

Preferred filter media 26 usable in the primary element 22 of aircleaner arrangement 1 is a type of media, described below, generallyreferred to as “z-media” or “z-filter media.” Z-filter media generallycomprises a corrugated or pleated media sheet secured to anon-corrugated facing sheet. The media is arranged to form a set oflongitudinal flutes or air flow channels on one side of the corrugatedor fluted media, and another set of flow channels on an opposite side ofthe media. In operation, flutes of one set of flutes are designated asinlet flutes, are left open at an inlet end or side of the media, andare sealed or otherwise folded closed at an outlet end or side of themedia. Analogously, the flutes of a second set of flutes are generallydesignated as outlet flutes, are sealed or otherwise closed at theoutlet end or side of the filter, and are left open at the outlet end orside of the filter. In operation, air passes into one flow face of theair filter construction, by passage into the open inlet flutes at anupstream end of the element. The air cannot flow out of the closed endsof these inlet flutes, so it must pass through the filter media into theoutlet flutes. The filtered air then passes outwardly from an exit endof the filter element, through the open ends of the outlet flutes.

A variety of shapes, i.e., outer perimeter configurations, for theprimary filter element 22 can be used. The particular one used thearrangement of the drawings, is an “obround” or “race track” shape. Itsdefinition will be understood by reference to FIG. 6, which depicts theelement. Referring to FIG. 6, the shape has first and second opposite,generally parallel, straight sections 38, 39, with opposite rounded(typically semicircular) end sections 40, 41. Alternative configurationsinclude, for example, oval and circular.

Referring to FIG. 5, in general, the filter media 26 is a coiledtwo-layered construction 45, formed from a flat (non-corrugated) sheet46 secured to a corrugated sheet 47. In general, on one side 48 of thecorrugated sheet 47 a first set of flutes 49 is formed; and on anopposite second side 50, a second set of flutes 51 is formed. In FIG. 5,edge 53 would correspond to inlet face 23, FIG. 2; and, edge 54 wouldcorrespond to outlet face 24, FIG. 2. The phantom lines in FIG. 5,indicate where and how the two-layered construction 45 has come backaround itself, as a result of the coiling; the solid lines being anouter layer of the two layers depicted. In alternate embodiments, thefilter media can be a stacked construction instead of coiled. Stackedconstructions include a plurality of: a flat sheet 46 secured to acorrugated sheet 47 stacked on top of each other.

The first set of flutes 49 would be sealed adjacent edge 54 by a sealantbead, or similar structure, not shown. The second set of flutes 51 issealed adjacent to the first edge 53 by sealant bead 55, as indicated.

From review of FIGS. 2 and 5, it should be apparent how the media 26functions. In general the first set of flutes 49 are open at inlet face23, and thus comprise inlet flutes. They would be closed at their exitends 54, as a result of a sealant bead or similar closure at thislocation. Thus air which enters flutes 49 at the inlet edge 53 must passthrough the media 26 to escape from the inlet flutes 49. Upon passagethrough the media, filtering occurs and fluid flow enters a second setof (outlet) flutes 51, at a location downstream from the sealant 53.Outlet flutes 51 are open along edge 54, and thus the filtered fluidstream can flow out of the media 26. This type of construction isgenerally characterized herein as z-filter media. The z-filter media caninclude a plurality of flutes; each having an upstream portion adjacentto an inlet flow face and a downstream portion adjacent to an outletflow face; selected ones of the flutes being open at the upstreamportion and closed at the downstream portion; and selected ones of theflutes being closed at the upstream portion and open at the downstreamportion.

A variety of corrugation shapes and sizes can be utilized in the filtermedia 26. Examples include: corrugations resulting in straight flutes,in which the flutes are parallel to each other and do not change shapefrom one end to other; straight flutes having crushed or pinched ends;and tapered flutes, in which inlet flutes gradually converge from a wideend in direction to a narrow end with adjacent exit flutes divergingfrom a narrow end to a wide end, in the same direction. Various z-filtermedia configurations are described in the following references:

1. Standard flutes are depicted in U.S. Pat. No. 5,820,646; and U.S.Pat. No. 5,895,574.

2. Tapered flutes, flutes with crashed ends and other variations influte shapes are described in WO 97/40918, published Nov. 6, 1997.

The above references (i.e., U.S. Pat. Nos. 5,820,646; 5,895,524 and WO97/40918) are incorporated herein by reference.

Referring again to FIG. 2, the (primary) filter element 22 isserviceable. By the term “serviceable” in this context, it is meant thatthe filter element 22 can be removed from the air cleaner assembly 1,and either be refurbished or replaced. In typical systems, the filterelement 22 is periodically replaced, during a servicing operation, byinstallation of a new element.

In general, the filter element 22, FIG. 7 comprises three components:the main body or straight through flow construction 55, primarilycomprising media 26; a centerpiece, core 57, or other frameworkstructure attached to the media 26; and, seal or gasket member 28. Theseal member 28 is generally positioned to completely circumscribe themain body or construction 55, preferably adjacent to, i.e., within 10 mmof and preferably within 5 mm of, inlet face 23.

It is noted that in the figures, the main body or straight through flowconstruction 55 of the filter element 22 is shown schematically, in thecross sections. That is, flute detail is not depicted. As to flutedetail, it is not shown in any figures other than the example of FIG. 5and a portion of FIG. 15, for convenience. As indicated previously, avariety of flute shapes can be used. Examples depicting the ends of az-filter element, and sealing at those ends, are provided in thedrawings of U.S. Pat. No. Des. 396,098; U.S. Pat. No. 6,190,432; U.S.Pat. No. Des. D450,827; U.S. Pat. No. 6,235,195; U.S. Pat. No. D437,402and U.S. Pat. No. D450,828, all 6 of these references being incorporatedherein by reference.

Still referring to FIG. 7, in general the main body (or straight throughflow construction) 55 of the filter element 22 has an outer surface 56which generally either comprises a portion of the flat (i.e.,non-corrugated) sheet 46 used to form the coiled construction 45; or,some outer sheet or cover placed around the media 26.

Referring still to FIG. 7, the seal member or pinch seal or axial sealgasket 28, shown in cross-section, includes the following features:mounting aperture 60 (FIG. 8); and, axial seal region 61 (FIG. 7). Themounting aperture 60 includes inner pocket 63, by which the seal member28 is secured to framework 58.

The axial seal region 61 is positioned to be compressed axially betweentwo housing portions. For the particular air cleaner assembly 1depicted, these two housing portions comprise cover 7 and primary aircleaner section 9. Referring to FIG. 8, in particular, the compressionoccurs between peripheral end flange 70 on precleaner 8; and peripheralend flange 71 on primary air filter cleaner section 9. The compressionof the seal member 28 at this location is referenced as “axial” becauseof the direction of compression. In this context, the terms “axial,”“axial direction of compression” and variants thereof, are meant torefer to a compression that occurs as a result of compressive forcesdirected in the same direction as a direction directly from the inletface 23 to the outlet face 24.

Referring now to FIG. 7, axial seal member 28 generally includes firstand second opposite sides 75, 76 and outer annular surface 77. Alsopreferably, referring to FIG. 8, gasket 20 includes the mountingaperture 60. The aperture 60 includes the pocket 63. The pocket 63receives part of the framework 58 to secure the gasket 28 to the mainbody 52. In the embodiment depicted in FIG. 8, the pocket 63 includes achannel 88. The channel 88, in the embodiment shown, is bisected by thecenter axis 94 of the gasket 28. As such, in the preferred embodiment,the gasket 28 is symmetrical about the axis 94, including beingsymmetrical about the center of the channel 88. The pocket 63 allows forthe gasket 28 to be secured to and “locked” to the framework 58.

Referring now to FIGS. 6–8, one embodiment of the framework 58 isdepicted. In the embodiment shown, the framework 58 includes a framemember 96 that functions to secure the gasket 28 to the main body 52.The frame member 96 includes a band 98 (FIG. 8) forming a ring 100 (FIG.6) that extends completely, peripherally, around the main body 52.Extending from the frame member 96 is a projection 102 (FIG. 8). Theprojection 102 preferably extends completely, peripherally around thestraight through flow construction 52. The projection 102 receives thegasket 28. In particular, the projection 102 extends into and isreceived in a “snugged fashion” by the pocket 63.

Still in reference to FIG. 8, the frame member 96 includes a lip 108extending radially inwardly from the band 98. The lip 108 hooks over theouter peripheral edge 109 of the main body 52. As such, the lip 108 isan extension over at least a portion of the inlet end 23 of the filterelement 22. The lip 108 helps to secure the frame member 96 to the mainbody 52. The lip 108 is on one end 110 of the band 98.

On an opposite end 112 of the band 98, the band 98 includes a taperedsection 114. The tapered section 114 helps to allow for ease of assemblyof securing the frame member 96 to the main body 52. In particular, inpreferred embodiments, during assembly, the gasket 28 will be secured tothe frame member 96 by pressing the gasket ring 28 on to the framemember 96. This is done by pressing the pocket 63 of the gasket 28 overthe projection 102, until the gasket 28 is operably mounted onto theframe member 96. Typically, the gasket ring 116 will stretch somewhat tobe fitted over the frame member 96, and once properly seated onto theprojection 102, will be in tension to be tightly secured to the framemember 96.

The combination gasket 28 and frame member 96 is then mounted onto themain body 52. This is done by placing the frame member 96 over the inletend 23. The tapered section 114 allows this gasket 28/frame member 96combination to be mounted over the main body 52 without damaging theinlet end 23. The tapered section 114 helps to seat the frame member 96in place over the inlet end 23.

Preferably, the frame member 96 is secured to the main body 52 with anadhesive between the band 98 and the outer surface 56 of the main body52. The tapered section 114 also helps to hold any excess adhesive whenmounting the band 98 onto the main body 52. This helps to minimize anyunsightly appearance of excess glue being squeezed out from between theband 98 and the main body 52.

Still in reference to FIGS. 6 and 7, the preferred frame member 96 alsoincludes a cross-brace construction 122. The cross-brace construction122 helps to provide structural integrity and overall strength to thefilter element 22 in the region of the gasket member 28. It also canhelp to prevent “telescoping” of the filter media 26. Telescoping couldoccur when the media is coiled by having adjacent layers extend outfurther over other layers. The cross-brace construction 122 can help toprevent such telescoping. In the particular embodiment shown, thecross-brace construction 122 includes three braces 124, 125, 126 inextension from the lip 108 and extending over the inlet end 23. Thecross-brace construction 122, in combination with the other features,also contributes to an attractive, ornamental appearance.

It is anticipated that such a configuration for gasket 28, can be usedwith a variety of sizes of elements 22. Typical arrangements will beelements on the order of 10 cm to 60 cm long (in dimension between innersurface 23 and outer surface 24), and 10 cm to 50 cm wide (diameter ifcircular; longest dimension if race track, obround or oval).

1. Alternate Embodiment of Gasket and Frame Member

Referring now to FIGS. 9 and 10, an alternate axial seal member 28′ isdepicted. Seal member 28′ generally includes first and second oppositesides 75′, 76′ and outer annular surface 77′. Preferably theconfiguration of the gasket 28′ is such that on each side 75′, 76′ thereis a corresponding projection, knob, or rib 85′, 86′ formed. Preferablyeach of ribs 85′, 86′ is continuous, i.e., extends continuously aroundthe straight through flow construction 52.

The projection 102′ on the framework 58′, in preferred embodiments, hasa shape that corresponds to the shape of the pocket 63′. As such, theprojection 102′ includes a stem 104′ and a head 106′.

The gasket 28′ will be secured to the frame member 96′ by pressing thegasket 28′ on to the frame member 96′. This is done by pressing thepocket 63′ of the gasket 28′ over the projection 102′, until the gasket28′ is operably mounted onto the frame member 96′. Typically, the gasket28′ will stretch somewhat to be fitted over the frame member 96′, andonce properly seated onto the projection 102′, will be in tension to betightly secured to the frame member 96′.

A number of advantages result from utilizing gasket arrangements 28 and28′ such as those described above. For example:

1. Because the gasket 28 is located at adjacent inlet end 23, region118, FIG. 4, i.e. the space between the element 22 and housing 9 is aclean air region. This means dust will not collect in this region, toadvantage. The result for example is not likely to have significant dustcontamination in the clean air region 32, during cleaning.

2. Because gasket 28 is axial, there is no need to provide a substantialdimension of extension of the gasket between the element body 52 and theinside surface 120 of housing 9, FIG. 4. This means that the dimensionof spacing in region 118 between the wall 10 and the body 52 can berelatively small, the order of 10 mm or less, typically 6 mm or less,preferably 2 mm or less.

A variety of materials for the filter media 26 are possible. One usablemedia 2 comprises cellulose media with the following properties: a basisweight of about 45–55 lbs./3000 ft² (84.7 g/m²), for example, 48–54lbs./3000 ft²; a thickness of about 0.005–0.015 in, for example about0.010 in. (0.25 mm); Frazier permeability of about 20–25 ft/min, forexample, about 22 ft/min (6.7 m/min); pore size of about 55–65 microns,for example, about 62 microns; wet tensile strength of at least about 7lbs/in, for example, 8.5 lbs./in (3.9 kg/in); burst strength wet off ofthe machine of about 15–25 psi, for example, about 23 psi (159 kPa). Thecellulose media can be treated with fine fiber, for example, fibershaving a size (diameter) of 5 microns or less, and in some instances,submicron. A variety of methods can be utilized for application of thefine fiber to the media. Some such approaches are characterized, forexample, in U.S. Pat. No. 5,423,892, column 32, at lines 48–60. Morespecifically, such methods are described in U.S. Pat. Nos. 3,878,014;3,676,242; 3,841,953; and 3,849,241, incorporated herein by reference.If fine fiber is used, one application would be to apply enough finefiber until the resulting media construction has the followingproperties: initial efficiency of 99.5% average, with no individual testbelow 90%, tested according to SAE J726C, using SAE fine dust; and anoverall efficiency of 99.98% average, according to SAE J726C.

2. Core Construction

In reference now to FIGS. 6, 7, 20, and 22, a usable core construction57 is shown. The core construction 57 is utilized to support the media26 and to help provide the desired resulting outer shape for the primaryelement 22. As will be explained below, the filter media 26 can beconfigured to define a receiving socket 130 to help center the filterelement 22 when orienting the element 22 in the air cleaner 9. Thereceiving socket 130 defined by the media 26 in the primary element 22can be used to align with a projection extending from the interior ofthe air cleaner housing 2. In particular preferred embodiments, theprojection will be part of the safety element 20. This is explainedfurther below, in Section C(2).

A variety of core constructions 57 are usable. The particular oneillustrated can be used to advantage. In the core construction 57 thatis shown, the core construction 57 is usable to help support thereceiving socket 130. In particular, in the one depicted, the coreconstruction 57 includes a non-cylindrical member 132. In FIG. 22, themember 132 includes at least one region of opposing walls 134, 135defining an open volume 136 therebetween. The open volume 136 functionsas an open receiver 138. In the preferred configuration shown, thereceiver 138 aligns and supports the receiving socket 130 defined by themedia 26. In the one shown, each of the receiving socket 130 and thereceiver 138 is non-cylindrical. By the term “non-cylindrical”, it ismeant that the cross-section does not form a circle. Rather, thecross-section is non-circular. In the preferred embodiment shown, thecross-section of the receiving socket 130 and the receiver 138 iselongated, with the opposing walls 134, 135 defining a gap of not morethan 20 mm., at least greater than 2 mm., and typically 3–12 mm.therebetween. The opposing walls 134, 135 are joined by curved ends 140,141, as can be seen in FIG. 6.

The core construction 57 illustrated includes structural molding 144(FIG. 7) for providing strength. The preferred embodiment also includesa molded plug 148 to ensure that fluid to be filtered cannot leak bypassage between the walls 134, 135 of the core 57. The molding 144further includes, in the particular preferred embodiment illustrated,centering structure 150. In the embodiment illustrated in FIG. 7, thecentering structure 150 has an apex 152 that is located about midwaybetween the ends 140, 141 of the core construction 57. The centeringstructure 150 will interact with projections in the housing 2 to helpalign and center the filter element 22 when installing the element intothe air cleaner 1.

In the preferred embodiment, the centering structure 150 divides thereceiver 138 into first and second receiving pockets 164, 166. Thereceiving pockets 164, 166, in the preferred embodiment, each receive aprojection to assist with centering and properly aligning the primaryelement 22 in operable orientation in the air cleaner 1.

In many usable embodiments, the distance between the ends 140, 141 ofthe core construction 57 is not greater than 24 cm., at least 5 cm., andtypically 7–15 cm.

Preferred core constructions 57 can also include at least one corrugatedregion 154 (FIG. 20) molded as part of the wall 134. The corrugatedregion 154 includes at least one, and preferably 2–10 corrugations 156that match the corrugation of the corrugated sheet 47 of the media 26(FIG. 5). Preferred core constructions 57 include two corrugated regions154, 158. The second corrugated region 158 also includes at least twocorrugations 159. The corrugated regions 154, 158 assist inmanufacturing of a coiled construction, resulting in the primary element22. To make the coiled construction, the corrugated side of the filtermedia 26 is aligned with the corrugated regions 154, 158. The media 26is then wound around or coiled around the core construction 57. Themedia 26 is secured to the core construction by using, for example, anadhesive bead at regions 160, 161 between the core constructions 57 andthe media 26.

In some embodiments, the primary filter element 22 is covered by anouter protective wrap covering the outer sidewall 25

One eye-catching, distinctive filter element 22 that is usable herein isdepicted in commonly assigned U.S. design patent application filed onApr. 2, 2003, carrying attorney docket 758.1520US01; entitled FILTERELEMENT; Express Mail No. EV 143555756 US; incorporated by referenceherein.

C. Usable Safety Elements

1. Example Embodiment, FIGS. 11–14

In reference now to FIGS. 11–14, an embodiment of a usable safetyelement 20 is illustrated. In preferred systems, the safety element 20is oriented in the air cleaner 1 downstream of the primary filterelement 22 in order to protect downstream components from debris thatcould get passed the primary filter element 22, in case of failure ofthe primary filter element 22. In addition, the safety element 20 helpsto protect the engine while servicing the air cleaner 1 while preventingdebris from falling into the clean air region 32.

The safety filter element 20 has an outside periphery 170 thatpreferably matches the outside periphery of the primary filter element22. In the embodiment illustrated, the safety element 20 is obround orracetrack shaped, but can be other shapes such as circular. Theracetrack shape of the safety element 20 includes a pair of straightsides 172, 173, joined by a pair of rounded or curved ends 174, 175.

In the illustrated embodiment, the safety element 20 includes a rigid,structural frame 178. Forming a portion of the frame 178 is a skirt orband 180. The band 180 circumscribes an internal region of filter media184. A variety of types of media 184 can be utilized. In theconfiguration shown, the media 184 is pleated, with the pleats 185extending between the straight sides 172, 173. Usable configurationsinclude at least 10 pleats, no greater than 50 pleats, and typically15–30 pleats. This can correspond to pleat densities of at least twopleats per inch, and typically 3–8 pleats per inch. In FIG. 11, it canbe seen how there are two regions of pleats 186, 187. The first pleatregion 186 is separated from the second pleat region 187 by a partition188 of the frame 178 that generally bisects the safety element 20. Thebisecting wall 188 extends longitudinally along the safety filterelement between curved end 174 and curved end 175.

In the preferred embodiment, the safety filter element 20 includes ahandle 190 that is sized to accommodate at least a portion of a humanhand. By “sized to accommodate a portion of a human hand”, it is meantthat the handle 190 has structure between it and the remaining portionof the safety element 20 that allows at least a part of hand (a fingeror fingers) to fit between the handle structure and the remainingportion of the safety element 20 to allow for manipulation of the safetyfilter element 20.

In the embodiment shown, the safety filter element 20 includes thehandle 190 projecting from the frame 178. In preferred embodiments, thehandle 190 is an integral extension of the partition 188. A variety ofhandle constructions 190 are usable. In the one shown, the handle 190has at least one projection 192 extending from the frame member 189. Theprojection 192 can take various configurations, including knobs, rings,extensions, etc. In the one shown, the projection 192 takes the form ofan arm 194 defining a void 196. In preferred embodiments, the void 196goes completely through the arm 194.

In particular preferred embodiments, the handle 190 includes a secondprojection 198. The second projection 198 can also take a variety ofshapes or configurations. In the one shown, the projection 198 has thesame shape as projection 192, in the form of an arm 202 having a void204 therebetween.

The sizes of the voids 196, 204, in preferred embodiments, are largeenough to accommodate a gloved finger of a human hand, to assist withmanipulation of the safety element relative to the air cleaner 1. Forexample, the voids 196, 204 define a cross-sectional area of at least 2cm², typically 4–100 sq. cm². The projections 192, 198 are separatedfrom each other by a landing 206 in the partition 189.

In preferred uses, the volume 205 defined by the landing 206 and theinner sides 207, 208 of each projection 192, 198 accommodates the apex152 (FIG. 7) of the centering construction 150 of the core 57. In suchpreferred uses, the projections 192, 198 operate as guides 212, 214 tohelp operably orient the primary filter element 22 in place in the aircleaner 1. The guides 212, 214, along with the centering structure 150help to center and place the filter element 22 within the air cleaner 1.This is explained further below in Section C(2).

Still in reference to FIGS. 11–14, the preferred safety element 20includes a seal member 218 to help form a seal 220 (FIG. 4) between thesafety element 20 and the air cleaner section 9 of the housing 2. In theone shown, the seal member 218 is secured to the band 180 around theentire periphery of the band 180. The seal member 218, in the one shown,forms a radially directed seal 221 (FIG. 4) between and against the band180 and the inside surface 120 of the air cleaner section 9 of thehousing 2. The seal member 218 includes at least one step 224 to assistwith installation and removal of the safety element 20 into the region32 (FIG. 4).

The safety filter element 20 can also be useful in preventingtelescoping of the filter media 26 from the primary filter element 22.The air flow pressure as it flows downstream may create a force on theelement 22 urging it to telescope. The safety filter element 20, whenarranged adjacent to the downstream end 24, can help to prevent mediatelescoping.

Useful media 184 can include many different types of conventional filtermedia. This includes cellulose, synthetic, and various blends. Oneusable, convenient media is a synthetic/glass fiber blend having aweight of 70±4.0 lb./3,000 ft.² (114±6.5 g/m²); a thickness of0.032±0.003 in (0.81±0.08 mm); a Frazier permeability of 165±20 ft./min.(50.3±6.1 m/min.); a pore size of 100±8 microns; a dry tensile strengthof 19.8±6.6 lb./in (9.0±3 kg/in); and a burst strength of 20±5 psi(138±34 kPa).

One eye-catching, distinctive safety filter element 20 that is usableherein is depicted in commonly assigned U.S. design patent applicationfiled on Apr. 2, 2003, carrying attorney docket 758.1521US01; entitledSAFETY FILTER ELEMENT; Express Mail No. EV 143555760 US; incorporated byreference herein.

2. Aligning/Centering Features with Primary Filter

In reference now to FIGS. 15–22, the interaction between the primaryfilter element 22 and the safety filter element 20 is illustrated. Asdiscussed above, the primary filter element 22 defines a receivingsocket 130 formed by a void in the media 26 when formed into the filterelement 22. The receiving socket 130 functions to receive guidestructure or centering structure to help properly mount the filterelement 22 within the air cleaner 1. The guide or centering structurecan include many different types of projections extending frominternally within the air cleaner 1. In the particular preferredconfiguration shown, the guide or centering structure is part of thesafety element 20. In particular, the guide or centering structure isembodied herein as guides 212, 214, which, are preferably also part ofthe handle 190 for the safety filter 20. It should be appreciated that,although the guides 212, 214 are shown as part of the safety element 20,in other embodiments, there can be other types of projections or guideswithin the air cleaner 1. Also as described above, in the preferredembodiment, the receiving socket 130 is aligned with core construction57 defining receiver 138.

In FIGS. 20 and 22, the guides 212, 214 can be seen projecting into andreceived by the receiving socket 130 and the receiver 138 of the core57. The apex 152 of the centering structure 150 can be seen extendingbetween each of the guides 212, 214 and toward the landing 206 in thevolume 205 (FIGS. 12 and 14) defined by the sides 207, 208 and landing206.

In use, after the safety element 20 is properly installed within the aircleaner 1, the primary filter element 22 is inserted into the aircleaner section 9 of the housing 2. The opening of the receiver 138 isaligned with the guides 212, 214. The guides 212, 214 enter the receiver138 into the receiving pockets 164, 166 (FIG. 7). The filter element 22is aided in proper orientation by interaction between the apex 152 ofthe centering structure 150 and the guides 212, 214. The filter element22, in preferred embodiments, is oriented so that the gasket 28 restsagainst the flange 71 of the air cleaner section 9 of the housing 2. Thecover 7 containing the precleaner section 8 is then oriented over theend of the air cleaner section 9 of the housing and clamped closed. Theclamping action causes compression of the gasket 28 between the flange70 and the flange 71 to create a seal therebetween.

Each of the primary filter element 22 and the safety filter element 20is removable and replaceable. Preferred methods for servicing aredescribed below.

D. Usable Precleaner Constructions

Attention is now directed to FIGS. 2–4, a preferred precleaner section 8is illustrated. While a number of different, conventional precleanerscan be used upstream of the primary filter element 22, the particularprecleaner 8 illustrated can be used to advantage.

As mentioned above, the precleaner 8 includes a plurality of centrifugalseparator tubes 13. Each of the tubes 13 include an outer surroundingsubstantially cylindrical wall 228 that is tapered between opposite ends229, 230. The end 229 has a smaller diameter than the end 230. The end229 will be oriented upstream to the end 230. Located within the wall228 is a vortex generator 232, including vanes or curved blades 234. Thewall 228 also includes at its downstream end 230 an outlet port 236.

Each of the tubes 13 is received within an upstream baffle plate 238.The baffle plate 238 includes a plurality of apertures 240 sized toreceive the upstream end 229 of the tubes 13. The upstream end 229 ofeach of the tubes has a tab 242 (FIG. 3) that is received within a slot244, which is part of the aperture 240. This tab/aperture forms anindexing arrangement 246 (FIG. 3) that ensures that each of the outletports 236 on each of the tubes 13 is pointed in the direction toward thedust ejection tube 4.

The preferred precleaner 8 depicted also includes a plurality ofextraction tubes 250 that are received within the tubes 228. Inpreferred implementations, each of the extraction tubes 250 is molded asan integral part of the cover 7. As such, in preferred embodiments, thecover 7 includes as an integral, molded, one-piece member: the side wall252, the tube 14, a downstream baffle plate 254, and each of theextraction tubes 250.

To assemble the precleaner 8, each of the tubes 228 is inserted into acorresponding aperture 240 in the baffle plate 238. The indexingarrangement 246 is used by aligning the tab of each of the tubes 228into a corresponding slot 244 to ensure that the outlet port 236 ispointed in a direction toward the ejector tube 4. The upstream baffleplate 238 with each of the tubes 228 installed therewithin is thenoriented over the remaining portion of the precleaner 8. Each of theends 230 of the tubes 228 is oriented over a corresponding extractiontube 250, and the baffle plate 238 is secured, such as by a snap fit,onto the side wall 252.

The precleaner 8 operates as follows: a gas flow stream containingparticulate matter flows through the upstream end 229 of each of thetubes 13. The flow is induced to rotate by the vortex generator 232. Therotating nature of the flow stream causes centrifugal forces to act onthe particulate matter in the gas flow stream. The particulate matterare heavier than the gas in the flow stream and migrates toward the wall228. The particles are ejected from the outlet ports 236, while theremaining gas stream flows through the extraction tubes 250. From theextraction tubes 250, the air flows downstream and into the upstreamflow face 23 of the primary filter element 22. The particulate matterthat is ejected from the outlet ports 236 falls by gravity downwardlythrough the ejection tube 4 and out through the ejection valve 15.

E. Methods

In general, a method of sealing a filter element having a straightthrough flow construction, as described, is provided. The preferredmethod generally includes positioning opposing flanges of a cover and aprimary air cleaner section, as described, in engagement with theprojecting axial seal gasket (on the element) and axially compressingthe gasket, as shown.

A method for mounting a sealing gasket on a filter element having astraight through flow construction, as described, is provided. Oneexample method generally includes providing a filter element having astraight through flow construction.

In one example method, a gasket is extruded, cut to length, and thenglued together to form a gasket ring. In other usable methods, a gasketis made from a moldable material, such as urethane foam and molded intoa desired shape. The gasket ring is then snapped over and pressed onto aframe member. Specifically, the projection 102 is squeezed into thepocket 63. Adhesive is placed on the outer surface 56 of the main body52 adjacent to the inlet end 23. The gasket 28/frame member 96 assemblyis then mounted onto the main body 52 over the inlet end 23, until thelip 108 engages the inlet end 23. The tapered section 114 helps to guidethe frame member 96 into place without damaging the main body 52.

To clean gas, first, the filter elements should be installed within theair cleaner. The cover 8, containing a precleaner, is removed from theair cleaner section 9 of the housing 2. The safety filter element 20 isprovided. The safety filter element 20 is handled and manipulated bygrasping the handle 190, such as putting fingers through the voids 196,204. The safety filter element 20 is placed through the open end of theair cleaner section 9 and installed within the portion 32. The gasket220 is compressed between and against the wall 9 to form a radial seal221 between the safety filter element 20 and the air cleaner section 9.

Next, the primary filter element 22 is provided. The primary filterelement 22 is manipulated such that the downstream end 24 is placedfirst through the open end of the air cleaner portion 9. The socket 130is aligned with the guides 212, 214 to be received therein. Inparticular, the core 57 has receiver pockets 164, 166 in the receiver138 that receive the guides 212, 214 therewithin. The centeringstructure 150 of the core 57 interacts with the guides 212, 214 to helpalign and center the primary element 22 within the air cleaner section9.

The primary element 22 is centered as described above and oriented suchthat the gasket 28 rests upon the flange 71 of the air cleaner section9. Next, the precleaner section 7 is oriented over the air cleanersection 9 so that the flange 70 rests on the gasket 28. The over centerlatches or clamps 17 are then used to apply axial force at joint 11 andform an axial seal with the gasket 28 between the precleaner section 7of the housing and the air cleaner section 9 of the housing.

To clean gas, the gas enters the precleaner 7 through the centrifugaltubes 13. The vortex generator 232 causes the gas flow to rotate, whichcauses the particulate matter to migrate toward the walls 28. Theparticulate matter is then ejected through the outlet ports 236 and fallby gravity through the dust ejector tube 14. The precleaned gas thenflows through the extraction tubes 250 and then through the inlet face23 of the primary filter element 22. The media 26 removes furtherparticulate material from the gas. The cleaned gas then flows throughthe outlet face 24. Next, the cleaned gas flows through the media 184 ofthe safety filter element 20, and then through the outlet tube 3. Fromthere, the cleaned gas flows to downstream equipment, such as an engine.

After a period of use, the air cleaner 1 will require servicing. Toservice the air cleaner 1, the precleaner section 7 is removed from theair cleaner section 9 of the housing 2. This is done by releasing theclamps. When the clamps are released, this releases the axial sealformed by the sealing gasket 28. The upstream face of the filter element22 is then exposed. The filter element 22 is grasped and removed fromthe air cleaner section 9. The primary filter element 22 can be disposedof or recycled, in convenient applications. If the safety filter element20 also needs servicing, the handle 190 is grasped, and the safetyelement 20 is removed from the air cleaner section 9 and disposed of orrecycled. It should be understood that in many applications, the primaryfilter element 22 will require replacement, while the safety filterelement 20 will not require replacement.

If the safety filter element is being replaced, then a second, newsafety filter element 20 is inserted into the housing 2, as described inthe initial installation description above. Next, a new primary filterelement 22 is provided and is installed within the air cleaner section9, as described above. The precleaner section 8 is placed over the aircleaner section 9, and the axial seal is formed with the gasket 28.

The above described principles can be applied in a variety ofembodiments and specific applications. From the general descriptionsgiven, alternate applications to those described in the drawings will beunderstood. The invention, therefore, should not be interpreted aslimited by the specification, but rather by the claims eventuallyissued.

1. An air cleaner comprising: (a) a housing including at least first andsecond portions; (b) a primary filter element operably installed withinthe housing; the primary filter element including a z-filter mediaconstruction having an inlet flow face and an outlet flow face; (i) thez-filter media construction including a plurality of flutes; each ofsaid flutes having an upstream portion adjacent to said inlet flow faceand a downstream portion adjacent to said outlet flow face; (A) selectedones of said flutes being open at said upstream portion and closed atsaid downstream portion; and selected ones of said flutes being closedat said upstream portion and open at said downstream portion; (ii) theprimary filter element having a cross-sectional configuration includinga pair of opposite curved ends joined by sides; (iii) the primary filterelement including a seal member extending completely, peripherallyaround the z-filter media construction; (A) the seal member includingfirst and second opposite sides and an outer annular surface; (B) theseal member being between the first and second portions of the housingto form an axial seal; (c) a precleaner upstream of the primary filterelement; the precleaner including multiple centrifugal separators and anejection tube; (i) each of the separators having a sidewall, an interiorvolume, and vanes within the interior volume; and (d) a safety elementoperably installed in the housing downstream of the primary filterelement; (i) the safety element including a frame having an outer,surrounding band; a gasket mounted to the surrounding band; a region ofpleated filter media within the frame; and a handle; (ii) the safetyelement having a cross-sectional configuration including a pair ofopposite curved ends joined by sides.
 2. An air cleaner according toclaim 1 wherein: (a) said precleaner comprises: (i) a first tube sheet;(ii) each of the separators being secured to the first tube sheet; (iii)a second tube sheet; (iv) each of the separators including a respectiveextraction tube integral with the second tube sheet.
 3. An air cleaneraccording to claim 1 wherein: (a) the z-filter media constructiondefining a non-cylindrical receiving socket in at least one of the inletflow face and the outlet flow face.
 4. An air cleaner according to claim1 wherein (a) the primary filter element has a cross-sectionalconfiguration including a pair of opposite semicircular ends joined bystraight sides.
 5. An air cleaner according to claim 1 wherein: (a) theprimary filter element includes a non-cylindrical core arrangementwithin the z-filter media construction; the core arrangement havingopposing walls.
 6. An air cleaner according to claim 5 wherein: (a) theopposing walls of the core arrangement define a socket.
 7. An aircleaner according to claim 5 wherein: (a) said core arrangement extendscompletely between said inlet flow face and said outlet flow face.
 8. Anair cleaner according to claim 1 further including: (a) a frame memberincluding a band around the z-filter media construction and a projectionextending radially therefrom; (i) said projection extending completely,peripherally, around said z-filter media construction.
 9. An air cleanercomprising: (a) a housing including at least first and second portions;(b) a primary filter element operably installed within the housing; theprimary filter element including a z-filter media construction having aninlet flow face and an outlet flow face; (i) the z-filter mediaconstruction including a plurality of flutes; each of said flutes havingan upstream portion adjacent to said inlet flow face and a downstreamportion adjacent to said outlet flow face; (A) selected ones of saidflutes being open at said upstream portion and closed at said downstreamportion; and selected ones of said flutes being closed at said upstreamportion and open at said downstream portion; (i) the primary filterelement including a seal member extending completely, peripherallyaround the z-filter media construction; (A) the seal member includingfirst and second opposite sides and an outer annular surface; (B) theseal member being between the first and second portions of the housingto form an axial seal; (c) a precleaner upstream of the primary filterelement; the precleaner including multiple centrifugal separators and anejection tube; (i) each of the separators having a sidewall, an interiorvolume, and vanes within the interior volume; and (d) a safety elementoperably installed in the housing downstream of the primary filterelement; (i) the safety element including a frame having an outer,surrounding band; a gasket mounted to the surrounding band; a region ofpleated filter media within the frame; and a handle; (A) the gasketforming a seal with the housing.
 10. An air cleaner according to claim 9wherein (a) the primary filter element has a cross-sectionalconfiguration including a pair of opposite semicircular ends joined bysides.
 11. An air cleaner according to claim 9 wherein (a) the primaryfilter element has a cross-sectional configuration obround in shape. 12.An air cleaner according to claim 9 wherein (a) the primary filterelement has a cross-sectional configuration oval in shape.
 13. An aircleaner according to claim 9 wherein: (a) the primary filter elementincludes a non-cylindrical core arrangement within the z-filter mediaconstruction; the core arrangement having opposing walls.
 14. An aircleaner according to claim 9 wherein: (a) the opposing walls of the corearrangement define a socket.
 15. An air cleaner according to claim 9wherein: (a) said core arrangement extends completely between said inletflow face and said outlet flow face.
 16. A method of filteringcomprising: (a) directing gas into a housing with a precleaner; theprecleaner having centrifugal tubes causing the gas to rotate andparticulate matter to be directed to a dust ejector tube; (b) directingthe gas from the precleaner through an inlet face of a primary filterelement and then through an outlet face of the primary filter element;(i) the primary filter element comprising z-filter media and having across-sectional configuration including a pair of opposite curved endsjoined by sides; (ii) the z-filter media including a plurality offlutes; each of the flutes having an upstream portion adjacent to theinlet face and a downstream portion adjacent to the outlet face; (A)selected ones of said flutes being open at the upstream portion andclosed at the downstream portion; and selected ones of the flutes beingclosed at the upstream portion and open at the downstream portion; (c)preventing gas from bypassing the primary filter element by an axialseal between the primary filter element and the housing; the axial sealbeing formed with a seal member extending completely, peripherallyaround the z-filter media; and (d) after flowing through the primaryfilter element, directing the gas through a safety element includingpleated media.
 17. A method according to claim 16 wherein: (a) the stepof directing the gas through a safety element includes directing the gasthrough a safety element including a frame having an outer, surroundingband; a gasket mounted to the surrounding band; pleated filter mediawithin the frame; and a handle.
 18. A method according to claim 17wherein: (a) the step of directing the gas through a safety elementincludes directing the gas through a safety element having a shapeincluding opposite curved ends joined by sides.
 19. A method accordingto claim 16 wherein: (a) the step of preventing gas from bypassing theprimary filter element by an axial seal between the primary filterelement and the housing includes using a seal member including first andsecond opposite sides and an outer annular surface.
 20. A methodaccording to claim 16 wherein: (a) the step of directing the gas throughan inlet face of a primary filter element and then through an outletface of the primary filter element includes directing gas through aprimary filter element having a non-cylindrical core arrangement; thecore arrangement having opposing walls.
 21. A method according to claim16 wherein: (a) the step of directing gas into a housing with aprecleaner includes directing gas into a precleaner having multiplecentrifugal separators; (i) each of the separators having a sidewall, aninterior volume, and vanes within the interior volume.